The present invention relates generally to a device for controlling print head movement and paper feeding in a printer, and, in particular, to a method and device for controlling actuation of a print head carriage motor and paper feed motor in a printer which operate in response to control commands from a host computer.
Devices for controlling the carriage motor and paper feed motor in a printer are known in the art. Such conventional devices operate such that control sequences of the carriage motor ("CR" motor) and the paper feed motor ("PF" motor) in a driving pattern are as shown in FIG. 1 of the drawings. Referring to FIG. 1, it is seen that the carriage motor accelerates during a period a to reach full carriage speed during period b and then decelerates during period c at which time the PF motor begins to accelerate during period e to a constant speed during period f. After period g when the PF motor decelerates to a rest position, CR motor once again begins to accelerate during period a and the cycle repeats until printing is completed.
Accordingly, after the paper feed action has completely terminated, the device judges whether or not the printer is in condition to print. Upon determining that the printer is in condition to print, the driving of the CR motor is started and printing begins in such conventional devices.
Such systems are slow and decrease the real print speed time of the printer because it is dependent on the drive time of the CR motor and its relation to the driving of the PF motor. In such conventional systems, the carriage does not start movement until paper feeding has ended. This reduces the actual printing speed of the printer.
Accordingly, it is desired to provide a carriage and paper feed control device and a method for a printer which eliminates the down time wasted as caused by the inadequate interaction between the two devices, thereby improving the actual printing speed of the printer.